In a typical electronics manufacturing process, circuitry including, but not limited to, printed circuit boards, flexible substrates, packages such as multichip modules (MCM), etc. may be populated with electronic devices using pick-and-place operations. For example, the circuitry may be routed through machines equipped with vision systems for identifying device placement locations in the circuitry and manipulators configured to pick up devices from a supply location (e.g., rail, reel, etc.) and place the devices into the previously identified device locations. Pick-and-place manufacturing has been effective at least from the standpoint of accurately populating circuitry with a variety of devices at a speed substantially faster than manual device insertion.
However, applications are now emerging wherein circuitry may need to be populated with high volumes of the same device. For example, recent developments in light emitting diode (LED) technology have created substantial demand for LED-based light sources due to their high quality light, low power consumption and long life. Manufacturing large-scale lighting (e.g., for commercial or professional use) may involve populating circuitry with thousands of the same LED. While pick-and-place manufacturing can do the job, high machine time and upkeep costs, limited production speed, etc. for performing such simple/repetitive assembly can be prohibitive.
Electronic manufacturing methods better suited for high volume production are now in development. For example, fluidic self-assembly (FSA) is a manufacturing method that relies upon the wetting behavior of liquids (e.g., solder) to populate circuitry. For example, electronic components (e.g., LED dies) may be assembled by drawing a circuit substrate through an agitated liquid bath. The liquid bath may be heated above the melting point of solder that has been pre-printed on the circuit board. Due to the agitation, bond pads on the components may randomly contact the molten solder on the circuit substrate, at which point the solder provides enough wetting and lubrication for the components to naturally find their device locations (e.g., their minimum energy configuration). In particular, the wetting effect of the melted solder may cause conductive pads or bumps on the devices to be drawn to conductive pads in the device locations.
Regardless of the type of manufacturing used, device misorientation is a problem that continues to plague device manufacturers with delays due to rework, device malfunctions due to incorrectly attached components, etc. Existing electronic components are orientation-dependent in that their pin/pad layout requires the component to be populated into circuitry in a particular orientation for proper component operation. For correct orientation, pick-and-place manufacturing may rely upon the components being properly oriented in their carriers (e.g., tubes, reels, etc.). However, devices are often incorrectly oriented in their carriers due to, for example, packaging errors, movement during shipment, etc. FSA manufacturing is even more problematic in regard to device orientation in that during population in FSA there is little control for device orientation.
Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications and variations thereof will be apparent to those skilled in the art.